Certain 2-(2',3',4'-trisubstituted benzoyl)-1,3-cyclohexanedione herbicides are described in U.S. Pat. No. 4,780,127, issued Oct. 25, 1988; U.S. Pat. No. 4,816,066, issued Mar. 28, 1989; and PCT International Publication No. WO 90/05712, published May 31, 1990 and entitled Certain 2-(2',3',4'-trisubstituted benzoyl)-1,3-cyclohexanediones, with William J. Michaely, inventor and all incorporated herein by reference.
The above-described herbicidal compounds can have the following structural formula ##STR1## wherein R is hydrogen, halogen or alkyl; R.sup.7 through R.sup.12 are hydrogen or C.sub.1 -C.sub.4 alkyl or R.sup.7, R.sup.8, R.sup.11 and R.sup.12 are methyl and R.sup.9 and R.sup.10 together are carbonyl; R.sup.1 is C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 haloalkyl, --CH.sub.2 CH.sub.2 OCH.sub.3, --CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5, --CH.sub.2 CH.sub.2 SCH.sub.3, or --CH.sub.2 CH.sub.2 SC.sub.2 H.sub.5 ; R.sup.2 is C.sub.1 -C.sub.4 alkyl; and n is the integer 0 or 2.
These herbicides can be prepared by reacting a dione of the structural formula ##STR2## wherein R.sup.7 through R.sup.12 are as defined with a mole of trisubstituted benzoyl chloride of the structural formula ##STR3## wherein n, R, R.sup.1 and R.sup.2 are as defined above.
This invention relates to a process for the preparation of 2-(hydrogen, halogen or lower alkyl)-3-(hydroxy, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 haloalkoxy, --OCH.sub.2 CH.sub.2 OCH.sub.3, --OCH.sub.2 CH.sub.2 OC.sub.2 H.sub.5, --OCH.sub.2 CH.sub.2 SCH.sub.3 or --OCH.sub.2 CH.sub.2 SC.sub.2 H.sub.5)-4-(alkylthio or alkylsulfonyl)-acetophenones and to the intermediates prepared by the process.